We compared a matched sample of heterosexual and lesbian, gay, and bisexual (LGB) students on 5 psychosocial adjustment composites, longitudinally across the transitional first year of college. Both LGB and heterosexual students experienced a significant increase in psychological distress over the first semester, along with significant decreases in psychological well-being and cognitive-affective strengths. Across the entire first year, LGB students demonstrated consistently greater psychological distress, greater cognitive-affective vulnerabilities, and less social well-being compared to heterosexual peers. This research indicates specific challenges that LGB students experience during the first year of university, suggesting opportunities for promoting successful transitions through this developmental milestone.